Radio communication device and printed board having at least one electronically conductive correction element

ABSTRACT

The invention relates to a radio communication device having at least one additional, current-conducting correction element connected to a printed board in the device. The correction element and printed board are configured in such a manner that a targeted, virtual current path elongation is brought about for an electric current induced on the printed board by electromagnetic radio fields of the antenna while the defined longitudinal and traverse dimensions of the printed board remain substantially unchanged.

BACKGROUND

Embodiments of the present invention relate to a radio communicationdevice having at least one printed circuit board of specified length anda specified transverse dimension accommodated in a housing and having atleast one antenna, coupled to said printed circuit board, for emittingand/or receiving electromagnetic radio fields.

Through the emission of energy from radio communication devices, acertain portion of the electromagnetic radio fields is usually alsoradiated into the human body. This is particularly true in cases ofmobile radio devices and cordless telephones such as, for example, thoseconforming to the DECT (Digital Enhanced Cordless Telecommunications)standard. Organic tissue in a user's head can in particular be exposedto impermissibly high levels of radio fields when the radiocommunication device is placed next to it. Limiting values for thermalenergy absorption have consequently been specified for human organictissue. What is termed the SAR (“Specific Absorption Rate”) rating isused as a criterion for measuring the radiation load to which respectiveusers are actually exposed. This rating indicates in watts per kilogramthe specific absorption rate at which a pre-definable area of tissuevolume is heated.

An exemplary embodiment of the invention describes a radio communicationdevice to be set in a better controlled manner in terms of itselectromagnetic radiation characteristics. A radio communication deviceis coupled to at least one additional, electrically conductivecorrection element via a printed circuit board wherein a targeted,fictive current-path elongation is produced for electric current inducedby electromagnetic radio fields of the antenna. Under the exemplaryconfiguration, the pre-defined longitudinal and transverse dimensions ofthe printed circuit board are substantially retained.

The local distribution of the resulting electric current on the printedcircuit board can in this way be better set in a targeted, (i.e.,controllable) manner.

The current-path elongation effected on the printed circuit board withthe aid of the additional, electrically conductive correction elementmakes it possible to influence the local current distribution there insuch a manner that any present local maximum of the electric current or,as the case may be, of a magnetic field associated with said current,can be displaced into a less critical area of the device and/or reduced.It further makes it possible to reduce or even substantially avoidimpermissibly intense “hotspots”, where areas of tissue volume havinghigher SAR values compared to such areas having lower SAR values, andhence reduce or even substantially avoid local variations in the thermalloading of areas of tissue volume—such as, for example, in the area ofthe respective user's head. By means of at least one such additionalcorrection element, the SAR distribution can, viewed overall, be made atleast more even or, as the case may be, more homogeneous compared to theSAR distribution of the same printed circuit board not having acorrection element. Improved antenna impedance matching of therespective radio communication device and hence improved energy emissioncan, moreover, be advantageously achieved, which is favorable inparticular when device dimensions are small with the device beingrelatively compact in design.

Other exemplary embodiments are described in the figures and text thatappear below.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention and its wide variety of potential embodiments will be morereadily understood through the following detailed description, withreference to the accompanying drawing in which:

FIG. 1 is a 3-dimensional schematic of a printed circuit board and aradio antenna, coupled thereto;

FIG. 2 is a schematic of the local distribution of the electric currentcontributing to the SAR effect which flows approximately along thelength of the printed circuit board shown in FIG. 1 when the mobileradio device is being operated;

FIG. 3 is a 3-dimensional schematic of a printed circuit board for aradio communication device to which board a correction elementelongating the current path in a manner according to the invention isadditionally coupled compared to the printed circuit board shown in FIG.1;

FIG. 4 shows the local distribution of the flow of electric currentalong the length of the printed circuit board shown in FIG. 3 having anadditionally coupled current-path elongating correction element;

FIGS. 5 to 7 are schematics of further exemplary embodiments ofcorrection elements according to the invention which are in each casecoupled to the printed circuit board of a radio communication device;

FIGS. 8 and 9 respectively show the course of the current flow along thelength of the printed circuit board shown in FIG. 1 not having andhaving a further, modified, current-path elongating supplementaryelement;

FIG. 10 is a schematic of a radio communication device according to theinvention having a printed circuit board and having an additional,current-path elongating correction element according to FIG. 9 placednext to a user's head; and

FIGS. 11 and 12 are each schematics of a printed circuit board having avariant form of the correction element coupled for virtual current-pathelongation.

DETAILED DESCRIPTION

Elements having the same function and mode of operation are identicallyreferenced in FIGS. 1 to 12.

FIG. 1 is a 3-dimensional schematic of a printed circuit board LP ascustomarily accommodated in the housing of a radio communication devicesuch as, for example, a mobile radio telephone or cordless telephone. InFIG. 10 a printed circuit board LP of this type is, by way of example,provided inside the housing GH of a mobile radio device MP shownschematically in a lateral perspective being used in keeping with itsintended purpose next to a user's head HE. The mobile radio device MP ispreferably a mobile radio telephone operating in particular according tothe GSM (Global System for Mobile Communications), IS95, IS136, IS2000,DCS1900, GPRS (General Packet Radio Service), EDGE (Enhanced Data Ratesfor GSM Evolution), or UMTS (Universal Mobile Telecommunication System)standard. The device is preferably dimensioned so as to be portable fora user and thus capable of being co-located with said user at changinglocations in the radio cells of radio communication systems of the abovetype. In addition to or independently of the voice-transmitting or, asthe case may be, telephoning functions of a mobile radio device of thistype, the device can, where applicable, also perform the function oftransmitting other messages such as, for example, data, images, faxmessages, e-mails, and the like.

The printed circuit board according to FIG. 1 may also be integrated inthe housing of another cordless telephone handling its communicationtraffic via radio with a local base station or other user devices.Cordless telephones of this type currently preferably operate accordingto what is termed the DECT (Digital Enhanced CordlessTelecommunications) or Bluetooth standard.

Viewed 3-dimensionally, the printed circuit board LP shown in FIG. 1 hassubstantially a flatly rectangular cuboidal shape, which is to say itsfour lateral edges SRL, SRR, SRO, SRU together form the external contourof a rectangle extending longitudinally further than its width. Thespatial geometry is clarified by additionally including the X, Y, and Zcoordinates of a Cartesian coordinate system as shown in FIG. 1, withthe X coordinate extending along the long sides SRL, SRR of the printedcircuit board LP and the Y direction running parallel to the wide sidesSRO, SRU of said board. The equipping area BF of the printed circuitboard LP is thus located substantially in the X, Y plane. The Zdirection is here assigned to the height or, as the case may be,thickness H of the printed circuit board LP with its various componentssuch as, for example, high-frequency module HB1 and evaluation/controlmodule HB2.

The rectangular shape of the printed circuit board is suitablepreferably for mounting in a flat, substantially cuboidal housing. Theprinted circuit board can have other external contours which, forpractical purposes, are generally selected to match the respectivegeometry of the housing of the respective radio communication device.

For the purpose of receiving and/or transmitting radio signals, theprinted circuit board has a high-frequency module HB1 with an antennaAT1 coupled to the area near the top half of its length as shown in theexemplary embodiment of FIG. 1. In the interest of a simplifiedrepresentation, the high-frequency module HB1 is indicated merely by adashed outline. Electromagnetic radio waves can be emitted into theradio space and/or detected coming from this space with the aid of thetransmitting/receiving antenna AT1. The antenna is connected via anelectrical contact lead COA (“hot conductor”) to the high-frequencymodule HB1 for the purpose of supplying energy, in particular for powerfeeding, and for controlling radio signals. Via a second electrical leadKS1 (“cold conductor”), said antenna simultaneously contacts at leastone ground area on the printed circuit board LP. A ground area of thistype can be formed by means of, for example, the metal housing cover or,as the case may be, screening cover of the high-frequency module HB1 orby means of a conductive layer provided either over the entire surfaceof the top or bottom side of the printed circuit board or on acontinuity-of-ground basis as an intermediate layer in the printedcircuit board LP. The contact leads are preferably configured so thatthe antenna AT1 is attached to the printed circuit board LP withsufficient mechanical stability, and will thus maintain its specifiedposition or, as the case may be, location ideally permanently. For thispurpose the contact leads can in particular be designed as supports soas to individually or jointly also assume a kind of flange functionmechanically securing the antenna AT1 to the printed circuit board.

In the exemplary embodiment shown in FIG. 1 the antenna AT1 ismechanically and electrically coupled to the top end face or, as thecase may be, wide side SRO of the printed circuit board LP with the aidof said contact leads COA, KS1. The antenna AT1 is here embodied as aplanar antenna. It is approximately rectangular in shape. With the aidof the mechanical connecting segments COA, KS1 it is positioned,proceeding from the top lateral edge SRO of the printed circuit boardLP, so as to project into a space enclosed by the four lateral edgesSRL, SRR, SRO, SRU along the plane normal in the Z direction. Theantenna's illustrated orthogonal projection onto the equipping area ofthe printed circuit board LP therefore lies substantially within theperipheral area BF bounded by the lateral edges SRL, SRR, SRO, SRU ofthe printed circuit board LP. Under this configuration, the antenna AT1does not project in a manner beyond the four lateral edges of theequipping area BF of the printed circuit board LP. One effect of thisconfiguration is that the surface of the printed circuit board isneither lengthened nor broadened by the coupled antenna. With the aid ofthe connecting segments, the antenna AT1 is inclined toward the printedcircuit board LP or, as the case may be, bent over, in such a manner asto lie like a further layer above and/or below the topology plane of theprinted circuit board LP within the space bounded by the four lateraledges. This antenna arrangement makes it advantageously possible toimplement particularly compact or, as the case may be, small devicedimensions.

Other electric modules may be accommodated in the second, bottom half ofthe printed circuit board LP shown in FIG. 1 which, in the interest of asimplified representation, are likewise indicated merely by a dashedoutline and designated HB2. These serve to control the input and/oroutput elements of the mobile radio device MP such as, for example, itskeypad, display, loudspeaker etc., and to process the radio signalsreceived and/or to be sent by means of the high-frequency module HB1.

In a printed circuit board of this type having a coupled antenna, thereis an associated, local total current distribution in the X direction,which is to say viewed along the length of the printed circuit board, asshown graphically in FIG. 2. The effective total current I(X) flowing ineach longitudinal locus X of the printed circuit board LP is summatedor, as the case may be, integrated over its total cross-sectional widthB in the X direction, and hence in the longitudinal direction of theprinted circuit board, is laid off along the abscissa. It is assumedthat this flow of electric current having the X direction as itspreferred direction is caused by H fields, which is to say by magneticfields arising locally in the near area of the antenna AT1 when it isoperating.

The origin of the X axis is assigned in FIG. 2 to the bottom lateraledge SRU of the printed circuit board LP shown in FIG. 1, whereas thetop lateral edge SRO corresponds to the length value X=L. In the area ofthe electrical contacting COA between the high-frequency module HB1 andthe antenna AT1 the feed or, as the case may be, base current FSI≠0flows toward the antenna AT1 at the longitudinal point X=L; because adefined feed current FSI is injected from the high-frequency module HB1into the base of the antenna AT1. In contrast to this, the flow ofcurrent in the longitudinal direction of the printed circuit board LP isinterrupted at its bottom free end by the boundary limitation, which isto say that I(X)=0 largely applies at the end face opposite the antennaAT1. In the preferred application of what is termed a λ/4 antenna, theelectrical field has a maximum at the bottom lateral edge or at the freeend SRU opposite the antenna. Owing to the geometry of the printedcircuit board LP having the shape of an extended rectangle, the largesteffective current amplitude for the SAR effect occurs along the centerlongitudinal axis ML approximately in the middle MI of the printedcircuit board LP, which is to say in the region of the intersection ofits diagonals, for the resulting summation current I(X) respectivelyintegrated via the cross-sectional width B. Viewed over the transversedirection Y of the printed circuit board, owing to skin and othercurrent-displacing effects the component of the current flow intensityin the X direction in the area along the two longitudinal edges SRL, SRRis greater than along the center line ML, with the distribution ofcurrent intensity on the longitudinal edges SRL, SRR being substantiallyaxially symmetrical to the center longitudinal axis ML. Said currentdistribution leads to an H field operative for the SAR effect or aresulting H field, to which the summation current I(X)—as shown in FIG.2—having a main concentration along the center longitudinal axis ML canbe assigned. The maximum of the effective current amplitude at thelongitudinal point X=MI is designated IM in FIG. 2.

A coupled structure of this type having with at least one antenna and atleast one electrically conductive printed circuit board connectedthereto therefore gives rise to locally inhomogeneous currentdistribution on the surface of the printed circuit board, and there arelocal variations in the intensity of summation current flow affectingthe SAR effect.

A measuring method described in detail in European standard proposalEN50361 (which incorporated by reference herein) is preferably used fordetermining the SAR ratings of mobile radio devices or, expressed in ageneral way, of radio communication devices, as the measure of thethermal heating of a specific area of tissue volume. The aim of thismethod is to identify the respective user's site of maximum thermalloading. The SAR rating is then produced by means of an integration overa specific, standardized volume of tissue at the location where themobile radio device MP is placed next to the respective user's head HEwhen being used in keeping with its intended purpose (see also FIG. 10).

Extensive tests using an electromagnetic measuring probe in a model headfilled with a simulation solution have shown that heating of the organictissue is subject to local variation, and has a local distributionhaving at least one maximum and/or minimum value. This locally varyingfield concentration is due at least in part to a local distribution,corresponding thereto, of summation current on the printed circuit boardLP such as, for example, I(X) shown in FIG. 2. An electric summationcurrent I(X) of this type preferably flows along the length of theprinted circuit board LP when the transmitting and/or receiving antennasuch as, for example, AT1 shown in FIG. 1 is embodied as a λ/4 antennaand forms a radiant dipole together with the printed circuit board LP.The effect of the printed circuit board in an initial approximation isthat of a kind of supplementary λ/4 antenna to the antenna AT1. Thelocal distribution I(X) of the flow of current operative for the SAReffect along length X of the printed circuit board LP is illustrated inFIG. 2. The near area is here the local area that is less than thedistance 2 D²/λ (λ is the wavelength; D is the device length). In, forexample, the GSM radio network having a frequency range between 880 and960 MHz (mid-frequency 900 MHz), the wavelength λ is approximately 35cm. In the PCN (Private Commercial Network) (E Network) having afrequency band between 1710 and 1880 MHz, the wavelength isapproximately 17 cm. The wavelength λ is approximately 15 cm in a UMTSradio communication system having a frequency transmission range between1920 and 2170 MHz. While the electromagnetic near field can be expectedto have a penetration depth of approximately 6 cm in the case of the GSMradio system on account of the local current distribution on the printedcircuit board, and approximately 5 cm in the case of the PCN network,the penetration depth of the near field is approximately 2 to 4 cm inthe case of a UMTS mobile radio device owing to the local currentdistribution on the main printed circuit board. The smaller the localdepth of penetration into the tissue, the greater the measured SARrating can become given the same assumed transmitter power of theantenna. This typically occurs because a higher electromagnetic fielddensity exists per specified tissue volume, which produces a largerflowing current, and hence produces a greater field concentration.

It is desirable to set electromagnetic radiation fields, in particularthe H field in the near area of the respective radio communicationdevice, and/or electric currents due thereto, in a more controlledmanner in terms of their local distribution.

FIG. 3 is a 3-dimensional schematic of another exemplary embodiment of acorrection element for virtually elongating the current path on theprinted circuit board LP shown in FIG. 1. The first correction elementis designated KV1 in FIG. 3. Under the exemplary embodiment, the elementis mounted on the narrower-bottom lateral edge SRU of the printedcircuit board LP that is situated opposite the other, narrower-toplateral edge SRO having the coupling of the antenna AT1. The elementpreferably has a substantially U-shaped profile. Toward both the top andthe bottom side of the printed circuit board LP a bridging element KV1or KV2 is running substantially vertically, which is to say along theplane normals Z of the top and bottom side of the printed circuit boardLP. Said bridging elements KV1, KV2 are mounted preferably symmetricallywith respect to the printed circuit board LP on its bottom end face SRU.Elements KV1, KV2 preferably run substantially along the entire width Bof the printed circuit board LP along its bottom lateral edge SRU. Thisprovides a beneficial coupling of the bridging elements in terms ofcharacteristic wave impedance. A substantially planar, second bridgingelement PST1 or PST2 is in turn attached to each transverse bridgingelement KV1 or KV2 in such a manner as to run substantially parallel tothe top or bottom side of the printed circuit board LP (=printed circuitboard equipping level) and to be positioned within the space bounded bythe four lateral edges of the printed circuit board. The second bridgingelements PST1, PST2 are thus substantially perpendicular to thetransverse bridges KV1, KV2 of width ZVB along the Z axis. Thecorrection element KV1 is in this way coupled both mechanically andelectrically to the printed circuit board LP.

Having a U-shaped profile, the correction element ZV1 is disposed in aroof-like configuration on the face end of the printed circuit board LPthat is opposite the printed circuit board end face SRO having theantenna coupling. Together with the antenna AT1 at the other end of theprinted circuit board LP, the roof-like covering of the printed circuitboard LP by the correction element KV1 forms a roof capacitance. Theoverall electrical structure includes the printed circuit board LP, theantenna AT1 coupled thereto, and the correction element ZV1 likewisecoupled to the printed circuit board to form a short rod antenna havingon its ends plate-shaped electrodes or, as the case may be, capacitorareas in the form of the antenna AT1, and the correction element ZV1.Owing to the effect of the correction element ZV1 as an additional endcapacitance, in electrical terms the printed circuit board LP isvirtually elongated so that a targeted, electric current-path elongationcan be provided for a summation current I(X) produced on the printedcircuit board LP by electromagnetic radio fields of the antenna AT1. Thesummation current is also operative for the SAR effect, because electricsummation current flowing along the length of the printed circuit boardLP—and in the X direction in the exemplary embodiment shown in FIG.3—can now additionally flow onto the expansion area of the correctionelement ZV1. As can bee seen in FIG. 3, corrective element ZV1 extendsfrom the front bottom edge SRU of the printed circuit board LP, and isfolded over and/or under the space bounded by the four lateral edges ofthe printed circuit board LP. The path length additionally provided bythe respective correction element (ZV1) from its area of coupling to theprinted circuit board to its front end forms a specific and desirableelongation of the current path defined by the original length (e.g., L)of the printed circuit board (e.g., LP).

In FIG. 3 the correction element ZV1 provides a path elongation ZVB inthe Z direction due to the respective transverse bridge KV1, KV2 and,additionally in total, by the further path length ZVL in the X directiondue to the respective bridging element PST1 or, as the case may be,PST2. The dominant factor for the electrical path elongation under theexample of FIG. 3 is the mechanical routing of the respective correctionelement proceeding from its area of coupling to the printed circuitboard LP to its front end measured in the imagined, non-folded planarstate of the correction element. The correction element extends thelength of the printed circuit board, although not in the originaltopology plane of the printed circuit board but, instead, into a spacewhich is bounded by the four lateral edges of the printed circuit boardand is situated above and/or below the peripheral area BF of the printedcircuit board. FIG. 3 also shows the path elongation which can beachieved by means of the total fold length of the correction element ZV1in the X and Z direction, which is to say in total by means of the pathsections ZVB and ZVL. A 30 percent elongation in a real trial can resultin an approximately 20 percent reduction in the SAR rating.

FIG. 4 is a schematic of local distribution of the flow of electriccurrent along the length of the printed circuit board shown in FIG. 3 inthe X direction, with the additional correction element ZV1 having beenattached to the printed circuit board LP. In contrast to the printedcircuit board LP shown in FIG. 1 which does not have a correctionelement and on which a resulting maximum current IM occurs approximatelyin the center of the length when X=MI, the effective current level nowflattens down at location X=MI. In the middle area MI of the printedcircuit board LP, the value I(X=MI)=IMD<IM. There is in particularhomogenizing of the local current distribution on the printed circuitboard LP viewed in the X direction under this configuration. Since aflow of current, here having I(X=0)=ID, is now also produced at thebottom end of the printed circuit board LP on account of the additionalcoupling of the correction element ZV1, the flow of current shifts or,as the case may be, extends to the outer, open end of the correctionelement ZV1. With the aid of the correction element ZV1 it is therebypossible to, in a defined manner, set a current level distribution I(X)between X=0 and L along the length of the printed circuit board having,viewed from one to the other front end of the printed circuit board, amore homogeneous, which is to say approximately more constant currentdensity compared to a printed circuit board according to FIG. 1 nothaving a correction element. FIG. 4 additionally shows the virtualcurrent-path elongation WV produced using the correction element ZV1measured from the area of coupling to the bottom end face SRU (X=0) ofthe printed circuit board LP to the outer, open end (X=L) of thecorrection element ZV1. The flow of current is not interrupted until atthe open front end of the supplementary element ZV1, so that thesummation current level is not substantially 0 until at that point. Thesummation current level I(X) along the elongation path WV isadditionally indicated in FIG. 4 by means of a dot-and-dash line. Saidlevel is formed by interpolating the values of the current level curvebetween the top and bottom end face of the printed circuit board LP,which is to say between X=0 and X=L, and the current level value of 0ampere at the free or, as the case may be, open end of the correctionelement.

In an initial approximation the virtual, electric current-pathelongation resulting from the additional coupling of the correctionelement such as, for example, ZV1, along the length, in the X directionin the exemplary embodiment here, is determined in particular by the sumof the path lengths of the correction element in the Z, X plane.Additionally thereto or independently thereof, the total area formed bythe respective correction element can also, influence the resultingoverall current length, because the larger the provided area of thecorrection element is, the greater the capacitive charging possibilitywill be and hence the facilitated current harmonizing on the printedcircuit board. Splitting of the current distribution on the printedcircuit board into two or more maxima may also be implemented underalternate embodiments without deviating from the spirit and scope of theinvention.

The correction element such as, for example, ZV1, can to practicaladvantage be embodied in a single piece. For this purpose it canpreferably be produced by bending or folding from an originally planar,electrically conductive element.

At least one electrically conductive element, which may be a single- ormulti-layer electrically conductive sheet, coating element, foil, and/orother electrically conductive surface or structural element ispreferably provided as the respective correction element such as, forexample, ZV1. It may it certain circumstances also suffice to provideone or more electrically conductive wires as the correction element.

In certain circumstances a virtual current-path elongation along thelength of the printed circuit board can also be effected by means of acorrection element which is not coupled over the entire wide side of theprinted circuit board LP to the end face opposite the antenna but,instead, is formed by means of a strip-shaped, electrically conductiveelement whose width is selected as being substantially less than that ofthe printed circuit board LP. FIG. 5 illustrates a 3-dimensionalschematic of a correction element of this type designated ZV2. Thestrip-shaped correction element ZV2 is embodied in meander form in theX, Y plane so that a relatively large current-path elongation can beprovided in the X direction, along the length of the printed circuitboard LP. The corrective element ZV2 is mechanically and/or electricallyconnected to the printed circuit board LP in the area of its frontbottom edge opposite the front top edge to which an outwardly projectingstub antenna AT2 is coupled. The correction element ZV2 can also becoupled to the printed circuit board LP by simple means by bending offor bending over a partial section of the printed circuit board groundarea. The meander-shaped correction element ZV2 is preferably kinked or,as the case may be, bent over along an end partial section byapproximately 90° with respect to its otherwise substantial planarity.This coupling section is designated KV2 in FIG. 5. The correctionelement ZV2 extends with its electrically conductive, substantiallyplanar surface for the most part in a plane which is substantiallyparallel to the topology plane of the printed circuit board LP. Adesired current-path elongation can be set in a controlled manner byappropriately selecting the meander shape, which is to say by selectingthe number of meander turns and/or selecting the length of those partialsections of the correction element ZV2 running substantially in thelongitudinal direction X or transversally thereto in the Y direction ofthe printed circuit board LP.

Viewed in general terms, a desired current-path elongation for a printedcircuit board of a specified length requiring to be maintained andspecified width requiring to be maintained can be provided in a targetedmanner by additionally coupling one or more correction elements to theprinted circuit board in such a manner that said correction element onlyextends into a space which is situated above and/or below the printedcircuit board and which is bounded by the lateral edges of said printedcircuit board. This produces a multi-layered structure, wherein theprinted circuit board and the respective correction element are stackedone above the other under the exemplary embodiment. The correctionelement can have one or more folds in one or more planes situated withinthe plane bounded by the lateral edges of the printed circuit board andarranged having a height clearance to said plane. In this way theprinted circuit board is not elongated or widened in its topology plane,wherein its originally specified dimensioning is largely maintained interms of its originally specified length and width.

For virtual elongation of ground it can, in certain circumstances, be ofpractical advantage to embody a partial area of the ground area of theprinted circuit board itself in such a way that an additional elongatingelement is produced. In FIG. 11, a correction element ZV6 of this typeis an integral part of the printed circuit board ground area of aprinted circuit board LP* having an originally rectangular externalcontour. A partial area of the ground area of the printed circuit boardLP* on the end face SRU of the printed circuit board opposite theantenna AT1 is here embodied as being separated from said board in thesame topology plane in such a manner as to act like an elongation of thecurrent path. The correction element ZV6 is given its meander shapethrough serially consecutive 90° kinks or, as the case may be,rectangular zigzag bending of bridge sections. Said meander-shapedcorrection element KV6 can be produced in particular by being punched orcut out from the originally rectangular printed circuit board LP shownin FIG. 1. The correction element ZV6 is preferably provided in a cornerarea of the bottom front of the printed circuit board SRU, said areabeing located transversely, in particular diagonally displaced inrelation to the antenna coupling in the corner area of the top, oppositefront SRO. This configuration creates an environment wherein asubstantially diagonal path between the antenna AT1 and the free end FEof the correction element ZV6 provides the longest possible virtual pathelongation for the summation current, operative in terms of the SAReffect, on the available printed circuit board area given the samespecified, rectangular external contour.

The current path can be set in a controlled manner by means of folds inthe respective correction element within the printed circuit boardequipping area and/or over the top and/or bottom side of the printedcircuit board. The correction element can be kept relatively short inthe X direction due to the meander shape, where in each case a partialsection extending in the longitudinal direction of the printed circuitboard alternates with a section that is transverse (i.e., orthogonal),to the length of the printed circuit board, with two such consecutivepartial sections enclosing between themselves an angle greater than zeroand in particular being mutually displaced by approximately 90°; becausethe zigzag shape allows a longer path to be achieved for the electriccurrent compared to a correction element having a straight strip shape.The maximum possible current path on the printed circuit board LP* shownin FIG. 11 starts in the area of the antenna AT1 and terminates at thefree end FE of the correction element ZV6 after traversing itsmeander-shaped turns.

If an antenna such as, for example, AT2 shown in FIG. 5, is coupled tothe printed circuit board LP in a corner area of its front end so as toproject outward along its length, it is of practical advantage tomechanically and electrically attach the correction element to theprinted circuit board in such a manner with respect to the antenna thatit will provide a current-path elongation substantially along thediagonal DIG, indicated by means of a dot-and-dash line, from the cornerarea of the antenna to the diametrically opposite corner area of thecorrection element ZV2 (see FIG. 5). The diagonal DIG is additionallyindicated in FIG. 5 by means of a dot-and-dash line. It describes themaximum path length that can be taken by an electric current on asubstantially rectangular printed circuit board such as, for example, LPshown in FIG. 5. The antenna AT2 is embodied in FIG. 5 as an outwardlyprojecting rod antenna. The current path can be efficiently elongatedthrough the mutually diagonally displaced arrangement of the antenna AT2and correction element ZV2. The length of the correction element in thelongitudinal direction of the printed circuit board can at the same timebe kept substantially compact, which is to say relatively short. Ameander-shaped correction element of this type preferably has a lengthpreferably between 1 and 4 cm.

The correction element may also be located laterally in a space on theperipheral area BF formed by the lateral edges SRL, SRR, SRO, SRU of theprinted circuit board LP, as illustrated in FIG. 1. By way of example,in FIG. 12 a correction element ZV7 is coupled to the right-hand longside SRR in the area of the corner ECK approximately diagonally oppositethe antenna AT1. The correction element ZV7 has a first partial elementWT secured substantially orthogonally referred to the peripheral area BFon the long lateral edge SRR. On the upwardly projecting end of saidfirst partial element WT is a second partial element DAC which is bentover with respect to the first partial element WT by approximately 90°and which projects into the peripheral area, or it forms the edge of thefirst partial element WT. It is thus arranged having a height clearanceto the printed circuit board equipping area and runs in the form of aroof-type partial cover substantially parallel to said area. The firstand second partial element WT, DAC can also be embodied as onecomponent. The bracket or, as the case may be, elbow-type correctionelement KV7 is produced by, for example, bending over an originallyplanar, electrically conductive element such as, for example, a coppersheet.

Other correction element geometries can also be of practical advantagefor reducing the SAR effect or for displacing undesired “hotspots” intoless critical areas of the device provided the respective correctionelement is coupled to the printed circuit board in such a manner thatits orthogonal projection with respect to the equipping area of theprinted circuit board LP will be substantially situated within theperipheral area BF bounded by the lateral edges SRL, SRR, SRO, SRU ofthe printed circuit board LP. In certain circumstances it can, forexample, suffice to omit the second partial element DAC and merely causethe first partial element WT to upwardly project enclosing an angle of90° or less with respect to the printed circuit board area at one ormore partial sections of one or more lateral edges. A correction elementof this type can in particular be formed by suitably bending over orflanging at least one lateral edge of the printed circuit board eitheralong a partial section or along its entire length. It can also beadvantageous to partially or completely raise up or, as the case may be,bend over the wide side—SRU in FIG. 12 here—which is opposite the frontof the printed circuit board having the antenna coupling.

FIG. 6 shows a further embodiment of an artificial current-pathelongation that does not itself elongate or widen the printed circuitboard in its topology plane. What is termed a PIFA antenna (PlanarInverted F Antenna) PIF is coupled to the printed circuit board LP asshown in FIG. 6 via a current feed point SS. The antenna PIF is then fedwith an electric current. The PIFA antenna PIF is arranged having aclearance to the topology plane of the printed circuit board LP. Underthe embodiment of FIG. 6, antenna PIF if oriented substantially planarand is substantially parallel to the topology plane of the printedcircuit board LP. The PIFA antenna is positioned in the area of the topfront end SRO of the printed circuit board LP. A ground area ZV3 islocated between the printed circuit board LP and PIFA antenna PIF sothat electric radio fields can be produced and decoupled into freespace. Ground area ZV3 extends substantially parallel to the topologyplane of the printed circuit board and PIFA antenna. Ground area ZV3 hasa transverse clearance with respect to the printed circuit board LP,which is to say a height D1 (preferably greater than 1 mm), and atransverse clearance D2 with respect to the PIFA antenna. Electricand/or magnetic fields that can be decoupled into space form between thePIFA antenna and the ground area ZV3 arranged having a transverseclearance to said antenna. The ground area ZV3 is connected in the areaof one of its front ends to the ground of the printed circuit board LP.The ground coupling is designated as KV3 in FIG. 6. An artificialelongation of the printed circuit board LP in terms of the availablecurrent path along its length can be provided by simple means byappropriately elongating the length of the ground area ZV3, present inany event, of the PIFA antenna PIF along the length of the printedcircuit board LP. As the PIFA antenna is arranged in two layers over thesurface of the printed circuit board, the overall result is amulti-layer structure that does not increase the original dimensions ofthe printed circuit board in terms of length or width but, instead,retains these dimensions.

FIG. 7 is a 3-dimensional schematic of the printed circuit board LPshown in FIG. 1 having a further correction element ZV4 whichelectrically elongates the electric current path along the length of theprinted circuit board LP, which is to say in the X direction along thelong sides of the printed circuit board LP in the exemplary embodiment,without altering the printed circuit board's original length or width.The correction element ZV4 is now formed by providing an electricallyconductive coating on the power supply unit, in particular arechargeable battery unit AK. A power supply unit of this type ispreferably embodied as being rechargeable. The power supply serves tosupply the electrical components and conductor paths on the printedcircuit board LP with electric current. A metallic coating on thesurface of the rechargeable battery can, for example, be provided alonga strip of extended rectangular shape as the electrically conductivecoating ME. The metallizing layer is connected to the printed circuitboard LP via electrical contacting means KV4. The electrical contactingmeans KV4 of the rectangular metallizing path are preferably provided inthe area of the front end of the printed circuit board LP in order toachieve as long as possible a flow path for the current. The maximumflow path provided for a current possibly flowing in the X directionextends here from the front end area of the printed circuit board LP inwhich the transmitting/receiving antenna AT3 is coupled to the oppositefront end to which the correction element ZV4 is electrically coupled;added to this is the strip length of the correction element in thelongitudinal direction X. The antenna AT3 is configured in the exemplaryembodiment as a planar or, as the case may be, flat antenna. A slottedmetal sheet or other electromagnetically conductive element ispreferably used for this purpose. The antenna AT3 can here be formed insuch a way as to function as both a dual-band and a multi-band antennafor transmitting and receiving electromagnetic radio waves withindifferent frequency ranges. The antenna AT3 is supplied with current inthe top area of the printed circuit board LP via an electric lead SS. Ata different location from this, another area of the flat antenna AT3 isconnected to the ground of the printed circuit board LP via electricalcontacting means MK.

An electrically conductive path is therefore additionally provided hereon the length WV* along the metallic coating ME in the X direction ofthe rechargeable battery unit AK, which is to say along the length ofthe printed circuit board LP. Viewed in total, the metallic coating MEon the rechargeable battery unit AK therefore effects a virtual electricelongation of the printed circuit board LP of length L by the pathlength WV*, with the original dimensions of the printed circuit board LPremaining. The dimensions also remain constant in terms of length andwidth since the additional elongation WV* is achieved by providing theadditional current-path elongating conductor path ME in a plane abovethe area of the printed circuit board itself. The metallization area MEcan be electrically linked or, as the case may be, contacted with theground of the printed circuit board LP by means of, for example,electric wires, foils, or other electrically conductive intermediateelements.

In the exemplary embodiment shown in FIG. 7, the metallic coating ME onthe exterior surface of the approximately cuboidal rechargeable batteryunit AK is applied only to a partial area of the exterior surface of therechargeable battery unit AK. It can equally be of practical advantageto apply the metallic coating ME over the entire top side of therechargeable battery unit AK. One or more or all surfaces of therechargeable battery can accordingly be partially or completely coatedwith a conductive coating of this type.

FIGS. 8 and 9 show exemplary displacements of what is termed the SAR“hotspot”, which is to say the local maximum in the local distributionof summation current along the length of the printed circuit board nothaving and having a current-path elongating correction element. FIG. 8shows in its top half a side view of the printed circuit board LP shownin FIG. 7 having the flat antenna AT3. The bottom half illustrates thelocal distribution of summation current I(X) occurring along the lengthof the printed circuit board in the X direction when a mobile radiotelephone is being operated. The X direction is assigned to theabscissa. The flat antenna AT3 is electrically coupled to the printedcircuit board LP at the left-hand front end of said board via a powersupply lead SS and the ground contact MK. As the antenna AT3 is activelysupplied with current in the area of said front end of the printedcircuit board LP, the flow of current is greater than 0 ampere at theleft-hand lateral edge of the printed circuit board LP. The summationcurrent level reaches a local maximum IM1 at the point X=XM1 toward thecenter of the length of the printed circuit board LP of total lengthX=L. The total current density in the direction toward the end of theprinted circuit board LP opposite antenna AT3 then drops until the flowof current is interrupted at the point x=L at the right-hand lateraledge so that I(X)=approximately 0 A. The overall result along the lengthof the printed circuit board is therefore a distribution of summationcurrent SV(X) having a local maximum at X=XM1 in the half of the printedcircuit board assigned to the antenna.

If an additional electrically conductive correction element ZV5 is nowelectrically linked or coupled to the front end of the printed circuitboard LP opposite the facing, second front end area of the printedcircuit board LP having the antenna coupling, depending on thedimensions, shape, positioning, and other material parameters (such as,for example, conductivity) of the correction element ZV5 it will bepossible to displace at least the original local maximum along thelength of the printed circuit board LP in the X direction. This is shownby the local current distribution SV*(X) in the bottom half of FIG. 9.The X direction is protracted along the abscissa, while the totalcurrent density I(X) has been assigned for each locus X of theordinates. In FIG. 9 the current-elongating correction element ZV5 isformed by, for example, a wire element which, viewed from the side, isapproximately right-angled. Generally, the longer the length of the wireelement is selected in the X direction above the printed circuit boardarea, the greater the impact of the current-path elongation on accountof this additional conductor path will be. As a result, the localcurrent maximum IM2 is displaced in the X direction to the longitudinalpoint X=XM2>XM1. This makes it possible to alter the originally present,local distribution of the total flow of electric current on the printedcircuit board operative for the SAR effect by means of the correctionelement according to the invention in such a way that the current levelmaximum or current level maxima can at least be displaced into a lesscritical area of the device, or even that the current level distributionis evened out. Alongside an evening-out of the current curve it is alsopossible to achieve a reduction in the current maximum or, as the casemay be, maxima so that IM2<IM1 generally applies. As a result of this,the actual electromagnetic field distribution in the near area of themobile radio device can be set in a more controlled manner. In thepresent exemplary embodiment shown in FIG. 9, the current level maximumIM2 is displaced along the X direction, which is to say along the lengthof the printed circuit board LP, away from the antenna area into a frontend area opposite the other front end area of the printed circuit boardLP having the antenna coupling. The reason for this targeteddisplacement measure is that the radio communication device is generallyassigned in the area of the antenna coupling to the respective user'sear area, while the other front end of the radio communication device issituated in the respective user's cheek area and is separated from thisby a larger gap or, as the case may be, transverse clearance.

This effect of displacing what is termed the SAR “hotspot” with the aidof the at least one correction element is illustrated in FIG. 10. Afrontal schematic of the head HE of a user employing a mobile radiodevice MP it is illustrated with the mobile radio device MP beingpositioned against the cheek. The top end of the mobile radio device MPis assigned to the user's ear EA as that is where the loudspeaker of themobile radio device MP is generally housed. Also located inside thehousing GH of the mobile radio device MP is the high-frequency module ofthe printed circuit board LP having the transmitting/receiving antennasuch as, for example, AT3 shown in FIG. 9. In the bottom front end areaof its length facing away from the antenna area the printed circuitboard LP additionally has the current-path elongating correction elementZV5 according to FIG. 9. The local summation current distribution curvesaccording to FIGS. 8 and 9 not having and having a correction elementare additionally indicated by means of a dot-and-dash line inside thehousing GH. While in the case of a printed circuit board LP not having acorrection element the local current level maximum is situatedapproximately in the contact area AZ of the housing GH against therespective user's head HE, when the correction element ZV5 is presentthe local current maximum can be displaced in accordance with the localcurrent distribution curve SV*(X) toward the correction element ZV5 andhence taken away from the contact area and moved further toward thebottom end of the mobile radio device. Since, owing to the curvature or,as the case may be, arching of the respective user's head shape, thereis generally a gap between the printed circuit board in the housing GHat the bottom end and the user's cheek BA, the maximum of the currentdistribution is therefore at least displaced into an area of the housingGH which is less critical in terms of producing the SAR rating. Due tothe transverse clearance DB between the underside of the printed circuitboard LP and the user's cheek BA, a maximum of the current leveldistribution present there can become far less effective. While theprinted circuit board not having a correction element has the currentlevel distribution SV(X) with a current maximum at a location on theprinted circuit board having the transverse clearance DA to the user'scheek, the transverse clearance in the case of the printed circuit boardLP having the correction element ZV5 is now displaced in accordance withthe local current distribution SV*(X) to a longitudinal point where thetransverse clearance between the printed circuit board and therespective user's cheek is enlarged to the gap clearance DB>DA.

Displacement of the originally present local maximum on the printedcircuit board into an area having a larger gap clearance DB to therespective user's cheek than in the case of a printed circuit board nothaving a correction element has the following effect on the operativefields: In the area of the contact area AZ on the printed circuit board,a current possibly flowing on the printed circuit board causes anelectromagnetic power density PA through the correspondingly producedmagnetic H field of PA=½ ZFD H², where ZFD is the characteristic waveimpedance and H is the value of the magnetic field intensity. The powerdensity of the magnetic field H reduces in inverse proportion to thesquare of the clearance or, as the case may be, distance to the sourceproducing it through the flow of current. PA˜1/DA² thus applies in thearea of the contact zone AZ. PB˜1/DB² and applies analogously in thearea of the bottom half of the housing GH at the point of the displacedlocal current maximum to the power density of the H field produced bythe current maximum. Forming the ratio between the two power densitieswill produce the following correlation: PB/PA=DA²/DB². If the currentmaximum is then displaced into an area of the printed circuit boardhaving approximately twice the transverse clearance or, as the case maybe, gap clearance to the respective user's cheek so that DB=2 DA, thepower density PB will drop to a quarter of the original power density atthe original contact zone AZ.

Viewed along a normal axis to the printed circuit board area, the powerdensity in the area of the displaced current maximum of the current pathcurve SV*(x) will have a power density at the user's cheek which is onlya quarter that in the contact zone AZ of the housing GH where theprinted circuit board has the distance of the transverse clearance DAfrom the user's cheek. This corresponds to a lowering of the effectiveenergetic power density of approximately 6 dB, because PB/PA=¼=>10 logPB/PA=6 dB applies. If, therefore, the original local SAR-effectivecurrent maximum is displaced with the aid of the correction element intoan area of the printed circuit board having approximately twice thetransverse clearance to the respective user's head as originally, theoriginally effective power density will not only halve but will reduceto a quarter.

Under alternate embodiments, the shape of the housing GH of the radiocommunication device MP can be configured such that, in the area of thedisplaced current level maximum, it additionally has an outwardlyconvexly curved inner area pointing away from the user's head HE. Thetransversely axial clearance to the head, viewed along a normal axis ofthe printed circuit board area, can thereby be further increased so asto effect a further additional distance to the user's head where thedisplaced current maximum on the printed circuit board occurs.

The actual length of the respective correction element in itsnon-folded, most extended state is preferably selected to be between 10%and 90%, in particular between 10% and 50%, of the maximum possibleembodiment of the ground length of the printed circuit board. Thecorrection element therefore preferably has a length such as willproduce an elongation path that is 1.1 to 1.5 times the original lengthof the printed circuit board for an electric current possibly flowingalong the length of the printed circuit board. For an approximately 9 cmlong and 4 cm wide rectangular printed circuit board, the length of thecorrection element in its flat, non-folded state may be selected between1 and 8 cm, preferably between 1 and 5 cm.

The correction element can in particular also be embodied as beingmultiply kinked, angled or twisted like a screw (coiled). It can, asapplicable, be composed of partial lengths at different heights.

It can advantageously be coupled to the printed circuit board not onlygalvanically but also, in addition to or independently of this,capacitively, inductively and/or on a radiation basis with the samefunction and mode of operation in terms of the current-path elongatingeffect.

As described above, at least one additional, electrically conductivecorrection element is therefore coupled to the respective printedcircuit board and embodied in such a manner as to effect a targetedvirtual current-path elongation for an electric current flowing on theprinted circuit board induced by electromagnetic radio fields of anantenna, while at the same time substantially maintaining the printedcircuit board's specified length and width. It is thereby possible toset electromagnetic radiation fields, in particular the H field in thenear area, of the respective radio communication device, and/or electriccurrents due thereto, in a more controlled manner in terms of theirlocal distribution. For example, a local maximum of the electric currentoperative on the printed circuit board for the SAR effect can, in adefined manner, be displaced, reduced, and/or distributed among severallower extremes.

A relatively high SAR rating for a mobile radio device is due inparticular to inhomogeneities in the current distribution resulting onthe printed circuit board. As a result of at least one electricallyconductive correction element being additionally coupled to the printedcircuit board in a space bounded by said board's lateral edges, at leastone displacement of the at least one local current level maximum intoless critical areas of the housing, and/or a substantially homogeneousfield distribution along the length of the radio communication device isachieved while at the same time maintaining the printed circuit board'sstructural size or dimensions in terms of length and width. Thisadvantageously allows the measurable SAR rating to be further reduced.

An additional correction element is preferably coupled to the printedcircuit board and embodied in such a manner as to effect a fictive(virtual) current-path elongation for the electric current of a kindresulting in a desired reduction in the SAR (Specific Absorption Rate)rating in the printed circuit board's ambient domain.

The respective additional, electrically conductive correction element isin particular coupled to the printed circuit board such that saidelement's imagined orthogonal projection with reference to said board'sequipping area lies substantially within a peripheral area bounded bysaid board's lateral edges.

The electrically conductive correction element is for this purposepreferably located in a space within and/or above and/or below and/orlaterally in the peripheral area bounded by the lateral edges of theprinted circuit board. Due to the correction element's formation withthe printed circuit board, a type of multi-layered structure is producedwithout continuing and elongating or, as the case may be, broadeningsaid board's dimensions in either the longitudinal or the transversedirection, and thus retaining the original dimensioning in terms oflength and width.

Only in terms of depth as viewed, for example, in the Z directionaccording to the exemplary embodiment shown in FIG. 1, does theadditional correction element appear as a further layer on the printedcircuit board inside the housing of the mobile radio device.

The coupling according to the invention of at least one virtuallycurrent-path elongating correction element to the printed circuit boardof a radio communication device is advantageous particularly when radiocommunication devices such as, for example, mobile radio devices orcordless telephones are used in keeping with their intended purpose. Dueto controlling of the current-path elongation with the aid of thecorrection element, the magnetic field intensity in the near area of theantenna of the respective radio communication device and hence in therespective user's near area can be generated more homogeneously when theradio communication device is being used in keeping with its intendedpurpose and the SAR values reduced in the process. This, in turn,improves power emission.

The trend in the field of mobile radio technology is particularly towardmobile communication terminals of increasingly small volume and size.This is in particular reducing the length of the devices apart fromtheir width and depth. As the frequency range within which the radiodevice has to operate is pre-specified and thus remains unalterable,there is a reduction in the ratio of device length and wavelength. Thisinfluence results in reduced power emission for the respective device asthe effective length of the antenna is reduced. This could becompensated by increasing the power fed to the antenna; the effect ofthis, in turn, would be, however, that higher currents could flow on theprinted circuit board. This at the same time would in turn lead to anincrease in the SAR rating, which is undesirable. In contrast to this,the virtual current-path elongation according to an embodiment of theinvention by means of at least one correction element coupled to theprinted circuit board reduces what are termed the “hotspots” and/ordisplaces these into less critical zones on the device. The poweremission can be improved and the SAR values diminished thereby. Thecorrection element according to the invention can in certaincircumstances even be advantageously employed as a design element. Itcan, for instance, be co-integrated into the respective radiocommunication device's display facility or keypad.

Other approaches to a solution that may be possible alongside thecorrection element according to the invention in addition to orindependently of this include:

a) Increasing the distance between the areas of large current amplitudein the mobile radio device and in the user's head:

In devices having an external antenna, the current maxima are locateddirectly on the antenna. This approach consequently results in externalantennas that are located on the back of the device and are frequentlybent away from the respective user's head. In devices having anintegrated antenna, the antenna is accommodated inside the housing ofthe respective mobile radio device on the side of the printed circuitboard facing away from the user's head. Alternately, the printed circuitboard may be configured to be as deep as possible in the device tomaximize the distance between the printed circuit board and user's head.The distance between the printed circuit board and user's head is inparticular maximized at the place where the mobile radio device makesdirect contact with the respective user's cheek. Also, the printedcircuit board may be mounted relatively close to the rear deviceenclosure and provide it with as large as possible a gap clearance tothe top device enclosure. Too great a device thickness is, however, inpractice undesirable as it detracts from easy manageability. Moreover,on account of the specified dimensions of the radio devices the SARvalues can only be reduced to a limited extent using this approachalone.

b) Shielding the electromagnetic emissions in the direction of theuser's head:

The beam characteristics of the radio communication devices in thehorizontal plane are altered using this approach. The beam effectintensifies emission power in the direction of the rear of the deviceand reduces emission power in the direction of the user's head. Theeffect is discernible in integrated antennas having a full-coverageground area on the printed circuit board which acts as a reflector. Toolarge an increase in the beam effect is, however, undesirable in mobileradio antennas and is also subject to physical limitations astransmitting and receiving operations would otherwise be excessivelydisrupted.

c) Absorbing the electromagnetic emissions using lossy material in theareas responsible for high SAR values:

The use of this approach alone has the disadvantage, however, thatemissions produced by complex means may be destroyed again by simplemeans. This diminishes the performance of the mobile radio devices andwill lead, in particular to shorter standby and talk times, which isundesirable. Approaches of this type are known from, for example, EP 0603 081 A1.

d) Reducing the high-frequency currents or, as the case may be,re-distributing them. This approach advantageously allows a number ofvariants:

-   -   i.) The power emission and hence, simultaneously, the power        radiated into the user's head is reduced by simple means without        altering the radio device. The use of this approach alone is,        however, precluded by the specified minimal requisite output        power. A further reduction in the SAR rating thus does not        appear possible.    -   ii.) The printed circuit board is widened. Increasing the width        of the printed circuit board will bring about a reduction in the        current density, and hence a reduction in the SAR rating, with        the current intensity in the longitudinal direction of the        printed circuit board being retained. The use of this approach        alone is, however, ruled out for further reducing the SAR rating        on account of the specified dimensions of the housings for        mobile radio devices.

In addition, although the invention is described in connection withmobile telephones, it should be readily apparent that the invention maybe practiced with any type of communicating device, such as a personalassistant or even a PC-enabled device. It is also understood that thedevice portions and segments described in the embodiments above cansubstituted with equivalent devices to perform the disclosed methods andprocesses. Accordingly, the invention is not limited by the foregoingdescription or drawings, but is only limited by the scope of theappended claims.

1. A radio communication device comprising: at least one printed circuitboard accommodated in a housing; at least one antenna, coupled to saidprinted circuit board, wherein said at least one antenna emits and/orreceives electromagnetic radio fields; and at least one electricallyconductive correction element coupled to the printed circuit board,wherein said correction element produces a current-path elongation foran electric current induced on the printed circuit board byelectromagnetic radio fields of the antenna, and wherein the at leastone correction element is mounted in the area of a front end of theprinted circuit board which is opposite another front end of the printedcircuit board sharing the coupling area of the antenna; and wherein theat least one correction element is positioned so that its orthogonalprojection into an equipping area of the printed circuit board liessubstantially within a peripheral area bounded by the lateral edges ofthe printed circuit board.
 2. The radio communication device accordingto claim 1, wherein the current-path elongation for the electric currentproduces a reduction in the SAR (Specific Absorption Rate) rating in theambient domain of the printed circuit board.
 3. The radio communicationdevice according to claim 1, wherein the at least one correction elementis located in a space within and/or above and/or below and/or laterallyin the peripheral area bounded by the lateral edges of the printedcircuit board.
 4. The radio communication device according to claim 1,wherein one or more electrically conductive wires is provided as aconductive correction element.
 5. The radio communication deviceaccording to claim 1, wherein at least one single or multi-layerelectrically conductive foil, coating, and/or other electricallyconductive material is provided as a conductive correction element. 6.The radio communication device according to claim 1, wherein the atleast one correction element is coupled such that the current-pathelongation for an electric current has a main direction of flow alongthe length of the printed circuit board.
 7. The radio communicationdevice according to claim 1, wherein the printed circuit board issubstantially rectangular.
 8. The radio communication device accordingto claim 7, wherein the at least one correction element and the antennaare attached relative to each other to the printed circuit board in sucha manner as to be assigned substantially to two diagonally opposite,electrically effective corner areas of the printed circuit board.
 9. Theradio communication device according to claim 1, wherein the at leastone correction element and the antenna are attached to the printedcircuit board in such a manner that they together form an electric roofcapacitance.
 10. The radio communication device according to claim 1,wherein the at least one correction element is formed by means of anelongating element of U-profile type located in roof manner on the frontend of the printed circuit board facing away from the antenna.
 11. Theradio communication device according to claim 1, wherein the at leastone correction element is formed by means of an electrically conductiveelongating element which, proceeding from the printed circuit board, issingly or multiply folded and/or bent round in one or more layer planesinto a space within and/or above and/or below the peripheral area. 12.The radio communication device according to claim 1, wherein the atleast one correction element is meander-shaped.
 13. The radiocommunication device according to claim 1, wherein the correctionelement is formed by means of the separate antenna ground of a PIFA(Planar Inverted F) antenna.
 14. The radio communication deviceaccording to claim 1, further comprising a battery unit, wherein the atleast one correction element is formed by means of at least oneelectrically conductive coating on the rechargeable battery unit. 15.The radio communication device according to claim 1, wherein the atleast one correction element is attached as an integral part of theboard ground of the printed circuit board, and wherein the at least onecorrection element has a meander form.
 16. The radio communicationdevice according to claim 15, wherein a partial area of a ground area ofthe printed circuit board is separated from said board in the sametopology plane in such a manner as to provide an elongation of thecurrent path.
 17. The radio communication device according to claim 1,wherein the at least one correction element has a predetermined lengthto produce a path elongation that is 1.1 to 1.5 times the originallength of the printed circuit board for an electric current flowingalong the length of the printed circuit board.
 18. The radiocommunication device according to claim 1, wherein the at least oneantenna a λ/4 antenna or PIFA (Planar Inverted F) antenna which,together with the printed circuit board, forms a radiant dipole.
 19. Theradio communication device according to claim 1, wherein the at leastone antenna is a substantially planar internal antenna.
 20. The radiocommunication device according to claim 1, wherein the at least oneantenna is a rod antenna projecting outwardly from the housing.
 21. Theradio communication device according to claim 1, wherein the at leastone correction element is coupled to the printed circuit boardgalvanically, capacitively, inductively and/or on a radiation basis. 22.The radio communication device according to claim 1, wherein at leastone of the correction elements is embodied as a metallic coating on thehousing enclosures and/or other parts of the radio communication deviceand wherein the correction elements are linked to the radiocommunication device's ground system.
 23. A radio communication devicecomprising: at least one printed circuit board accommodated in ahousing; at least one antenna, coupled to said printed circuit board,wherein said at least one antenna emits and/or receives electromagneticradio fields; and at least one electrically conductive correctionelement coupled to the printed circuit board, wherein said correctionelement produces a current-path elongation for an electric currentinduced on the printed circuit board by electromagnetic radio fields ofthe antenna, wherein the at least one correction element is mounted inthe area of a front end of the printed circuit board which is oppositeanother front end of the printed circuit board sharing the coupling areaof the antenna.
 24. A radio communication device comprising: at leastone printed circuit board accommodated in a housing; at least oneantenna, coupled to said printed circuit board, wherein said at leastone antenna emits and/or receives electromagnetic radio fields; and atleast one electrically conductive correction element coupled to theprinted circuit board, wherein said correction element produces acurrent-path elongation for an electric current induced on the printedcircuit board by electromagnetic radio fields of the antenna, andwherein the at least one correction element is mounted in the area of afront end of the printed circuit board which is opposite another frontend of the printed circuit board sharing the coupling area of theantenna, and wherein the at least one correction element is formed bymeans of an elongating element of U-profile type located in roof manneron the front end of the printed circuit board facing away from theantenna.
 25. A radio communication device comprising: at least oneprinted circuit board accommodated in a housing; at least one antenna,coupled to said printed circuit board, wherein said at least one antennaemits and/or receives electromagnetic radio fields; and at least oneelectrically conductive correction element coupled to the printedcircuit board, wherein said correction element produces a current-pathelongation for an electric current induced on the printed circuit boardby electromagnetic radio fields of the antenna, and wherein the at leastone correction element is mounted in the area of a front end of theprinted circuit board which is opposite another front end of the printedcircuit board sharing the coupling area of the antenna, and wherein theat least one correction element is formed by means of an electricallyconductive elongating element which, proceeding from the printed circuitboard, is singly or multiply folded and/or bent round in one or morelayer planes into a space within and/or above and/or below a peripheralarea of the printed circuit board.
 26. A radio communication devicecomprising: at least one printed circuit board accommodated in ahousing; at least one antenna, coupled to said printed circuit board,wherein said at least one antenna emits and/or receives electromagneticradio fields; at least one electrically conductive correction elementcoupled to the printed circuit board, wherein said correction elementproduces a current-path elongation for an electric current induced onthe printed circuit board by electromagnetic radio fields of theantenna; and a battery unit, wherein the at least one correction elementis formed by means of at least one electrically conductive coating onthe battery unit.
 27. A radio communication device comprising: at leastone printed circuit board accommodated in a housing; at least oneantenna, coupled to said printed circuit board, wherein said at leastone antenna emits and/or receives electromagnetic radio fields; and atleast one electrically conductive correction element coupled to theprinted circuit board, wherein said correction element produces acurrent-path elongation for an electric current induced on the printedcircuit board by electromagnetic radio fields of the antenna, whereinthe at least one correction element has a predetermined length toproduce a path elongation that is 1.1 to 1.5 times the original lengthof the printed circuit board for an electric current flowing along thelength of the printed circuit board.